President didn't disclose 1st positive test, sources say

The president had already tested positive Thursday when he appeared on Fox News.

ByMatt Zarrell, Jon Haworth, Ivan Pereira, and Marc Nathanson
Last Updated: October 5, 2020, 7:58 AM EDT

President Donald Trump's condition is continuing to improve as he fights a coronavirus infection, doctors say, and he may be able to leave Walter Reed Medical Center as early as Monday -- even as details emerge that the president allegedly initially tested positive for COVID-19 earlier than he acknowledged.

Doctors also reported that Trump, over the course of exhibiting coronavirus symptoms, had earlier experienced two episodes of "transient drops" in his oxygen saturation.

Yet the president was feeling well enough Sunday evening to briefly leave Walter Reed for a surprise drive-by, waving to supporters outside the hospital.

Meanwhile, numerous questions remain about how many people at the highest levels of government had been exposed to the virus after a week of events involving the president where social distancing and mask-wearing were lax in the White House and elsewhere.

Sunday's headlines:

Here is how the news developed on Sunday. All times Eastern.
Oct 04, 2020, 8:04 PM EDT

Biden tests negative

Vice President Joe Biden's campaign said he underwent PCR testing today and the results came back negative.

The campaign wouldn't provide more details about the test.

-ABC News' Molly Nagle

Oct 04, 2020, 7:59 PM EDT

Barr is in self-quarantine, gets 3rd negative test result

Department of Justice spokeswoman Kerri Kupec told reporters that Attorney General Bill Barr is self-quarantining at home, but has so far tested negative for the virus.

The spokeswoman would not provide more details about Barr’s self-quarantine.

This is the third time he has tested negative for COVID-19 since last Tuesday's debate. Barr attended the Sept. 26 event at the White House where President Trump announced Judge Amy Coney Barrett as his Supreme Court Justice nominee.

Several Trump administration officials who contracted the virus last week, including Kellyanne Conway and former Gov. Chris Christie, attended the event and were not wearing masks during the outdoor ceremony.

Barr was photographed talking with Conway while not wearing a mask during the event.

-ABC News’ Alexander Mallin

Oct 04, 2020, 6:23 PM EDT

Trump did not disclose 1st positive test

Before making an appearance on Sean Hannity's show on Fox News Thursday evening, President Trump had already tested positive that evening for COVID-19 from a rapid test, multiple sources familiar with the matter told ABC News. 

The president did not reveal the results of his first positive test as he awaited results from the more accurate PCR test. However he confirmed to Hannity that top aide Hope Hicks had tested positive. 

"She did test positive. I just heard about this. She tested positive,” Trump said.

"And I just went out with a test, I’ll see -- you know, ‘cause we spend a lot of time -- and the first lady just went out with a test also," he said.

-ABC News' Katherine Faulders and John Santucci

Oct 04, 2020, 5:43 PM EDT

Trump leaves Walter Reed briefly for drive-by appearance

With little warning, President Donald Trump left Walter Reed Hospital for a few minutes in his motorcade Sunday evening to greet supporters who were outside.

Trump, appearing with a mask from the window of his vehicle, was seen waving to a crowd.

The president tweeted a video before the drive-by appearance thanking his supporters and saying he was going to "make a little surprise visit."

Trump also said in the video that he visited soldiers and first responders at the hospital.

It was not immediately known if there was anyone else in the car aside from the driver. A Secret Service spokesperson declined to comment on the impact of Trump’s trip on the health and safety of their agents, saying they "do not comment on presidential protection."

A senior administration official told ABC News afterward that Trump had returned to the hospital and that he had not been discharged.

Administration member Judd Deere subsequently put out a statement saying that, "President Trump took a short, last-minute motorcade ride to wave to his supporters outside and has now returned to the Presidential Suite inside Walter Reed."

There have been no updates on Trump's condition from his physicians since earlier in the day, when they told reporters he could be released as early as Monday.

-ABC News' John Santucci, Justin Fishel, Elizabeth Thomas and Jack Date